def f(n):
    if n <= 1:
        return  1
    else:
        return  n *f(n - 1)


num= int(input('请输入一个正整数：'))
s = f(num)
print(num, '的阶乘是：', s)


def fibo(n):
    if n <= 2:
        return  1
    else:
        return fibo(n - 1) + fibo(n - 2)


print('斐波那锲数列的第{}项为{}'.format(7,fibo(7)))




sum =lambda  a, b, c: a + b + c
print(sum(1, 2, 3))


fun = lambda m: m ** 2
print(fun(5))






